A rotary electric shaver, comprising: a main body having a grip part and a blade setting base; a motor built in the main body and connected to a first driven shaft; and a head connected to the blade setting base, wherein in the blade setting base, a plurality of second driven shafts are connected to the first driven shaft, the head has a setting part in which a plurality of blade units are disposed, and a blade frame that holds the setting part, each of the blade units has an outer blade part and an inner blade part, the inner blade part has an inner blade member in which a plurality of blade edges are formed in a circumferential direction, and a base part joined to the inner blade member, the second driven shaft is connected to the base part, and the inner blade member is configured to rotate around an axis passing through the second driven shaft, the outer blade part has an annular outer blade member having a sliding contact surface with which the blade edge comes into sliding contact and having a plurality of slits formed in the circumferential direction, a disk-shaped cover disposed inside the annular outer blade member, two to six balls disposed in the outer blade part, and a support that supports the two to six balls, the cover has two to six windows, wherein a part of each of the two to six balls surrounded by the cover and the support protrudes from a corresponding window of the two to six windows, and wherein each of the two to six windows has a smaller diameter than the corresponding ball in the two to six balls, and all of the two to six balls are disposed at positions deviated from the axis passing through the second driven shaft. a main body having a grip part and a blade setting base; a motor built in the main body and connected to a first driven shaft; and a head connected to the blade setting base, wherein in the blade setting base, a plurality of second driven shafts are connected to the first driven shaft, the head has a setting part in which a plurality of blade units are disposed, and a blade frame that holds the setting part, each of the blade units has an outer blade part and an inner blade part, the inner blade part has an inner blade member in which a plurality of blade edges are formed in a circumferential direction, and a base part joined to the inner blade member, the second driven shaft is connected to the base part, and the inner blade member is configured to rotate around an axis passing through the second driven shaft, the outer blade part has an annular outer blade member having a sliding contact surface with which the blade edge comes into sliding contact and having a plurality of slits formed in the circumferential direction, a disk-shaped cover disposed inside the annular outer blade member, two to six balls disposed in the outer blade part, and a support that supports the two to six balls, the cover has two to six windows, wherein a part of each of the two to six balls surrounded by the cover and the support protrudes from a corresponding window of the two to six windows, and wherein each of the two to six windows has a smaller diameter than the corresponding ball in the two to six balls, and all of the two to six balls are disposed at positions deviated from the axis passing through the second driven shaft.