We study dynamical properties of an ensemble of noninteracting particles in a time-dependent elliptical-like billiard. It was recently shown [Phys. Rev. Lett. 100, 014103 (2008)] that for the nondissipative dynamics, the particle experiences unlimited energy growth. Here we show that inelastic collisions suppress Fermi acceleration in a driven elliptical-like billiard. This suppression is yet another indication that Fermi acceleration is not a structurally stable phenomenon. DOI: 10.1103/PhysRevLett.104.224101 PACS numbers: 05.45.Pq, 05.45.Tp Fermi acceleration (FA) is a phenomenon that occurs when a classical particle acquires unlimited energy upon collisions with a heavy and moving wall. The original idea is due to Fermi [1] who assumed that the enormous energy of the cosmic particles comes from interactions with moving magnetic clouds. After that many different 1D Fermi accelerator models were studied [2][3][4][5]. Basically they are composed of a classical particle which experiences collisions with a moving wall. A source of returning for a next collision can be a fixed wall [3,4], a gravitational field [5], or both [6]. A simple generalization to 2D is to consider the dynamics of the particle inside a billiard domain that, depending on the shape of the boundary, demonstrates regular [7], mixed [8], or fully chaotic dynamics [9]. Applications of billiards to physical problems include superconducting [10] and confinement of electrons in semiconductors by electric potentials [11,12], ultracold atoms trapped in a laser potential [13][14][15][16], mesoscopic quantum dots [17], reflection of light from mirrors [18], waveguides [19,20], and microwave billiards [21,22].If the boundary is time dependent, the LoskutovRyabov-Akinshin (LRA) conjecture [23] claims that chaotic dynamics for a billiard with the static boundary is a sufficient condition to produce FA if a time perturbation of the boundary is introduced. This conjecture was confirmed in many models [24][25][26]. Recently, however, [27] a specific perturbation in the boundary of an integrable elliptical billiard led to the observation of a tunable FA. The result discussed in [27] was a break of two paradigms: (i) it was expected [28] that the elliptical billiard, which is integrable for static boundary and therefore demonstrates the most regular dynamics, does not exhibit FA; and (ii) since the static version of the elliptical billiard does not have chaotic dynamics, then the LRA conjecture [23] should be extended.In this Letter we show that the mechanism which produces FA in the time-dependent elliptical-like billiard can be broken by nonelastic collisions. Since the destruction is observed for very small dissipation, one can conjecture that FA is not a structurally stable phenomenon. We consider the dynamics of an ensemble of noninteracting particles in a time-dependent elliptical-like billiard. Our results show that initial conditions chosen along the separatrix curve of the billiard with a static boundary lead the particle to exhibit FA. Thus the LRA...