A fluid compressor having a cylinder, columnar rotating body, first and second spiral grooves, first and second recessed grooves, first and second spiral blades slidable in a radial direction of the columnar rotating body and fitted in the first and second spiral grooves. A drive means is provided for causing a rotational movement of the cylinder and the columnar rotating body synchronously with each other. Stoppers extend from the cylinder into first and second recessed grooves whose wall portions are located adjacent to a respective first turn of the second and first spiral grooves and advanced by 180.degree. from a respective second and first spiral grooves. The first and second stoppers engage respective end portions of the spiral blades during the rotational movements of the cylinder and the columnar rotating body. With this arrangement of the wall portions of the first and second recessed grooves, interference between adjacent first and second grooves is prevented and refrigerating gas compressed in an operating chamber does not leak or return to a first suction port provided in a central portion of the columnar rotating body.