Abstract: A wave cam type compressor is provided. The compressor has a wave cam body mounted on a rotary shaft for integral rotation and pistons operably contacting said cam body by way of shoes. The shoes are moveable relative to the cam body according to the rotation of the cam body. The shoes move on predetermined paths on cam surfaces of the cam body. The rotation therewith of the rotary shaft is converted into a reciprocation movement of the pistons between top dead center and a lower dead center in cylinder bores to compress fluid supplied into the cylinder bores. Each cam surface has a contour matching the locus of a predetermined smooth two-dimensional imaginary curve when the curve is translated from its plane in the direction perpendicular to the plane. A first portion is provided on the cam surface to drive the piston to the bottom dead center and a second portion is provided on the cam surface to drive the piston to the top dead center.