A fluid machine includes a rotary shaft, an operation body configured to discharge fluid by rotation of the rotary shaft, a housing accommodating the rotary shaft and the operation body, and a foil bearing disposed in the housing rotatably supporting the rotary shaft. The foil bearing includes a cylindrical bearing housing, a top foil between the bearing housing and the rotary shaft, and a bump foil between the bearing housing and the top foil and elastically supporting the top foil. The bearing housing has a protrusion protruding inwardly in a radial direction from the bearing housing. The protrusion includes an abutment surface configured to restrict deformation of the bump foil to an elastic range not to reach a plastic range by abutting against the top foil or the bump foil when the top foil is displaced outwardly in the radial direction of the bearing housing.