An electromotive unit includes a linear motor, a motor case containing the linear motor, a movable element connected with the linear motor and reciprocatingly driven with respect to the motor case, and a sealing material sealing the gap between the movable element and the opening of the motor case. The sealing material includes a contact portion contacting the movable element; and a recessed portion formed around contact portion, having a ring-shaped groove facing the outside of the motor case, and elastically deformable according to reciprocating movement of the movable element. This aspect provides an electromotive unit that hardly generates noise while the movable element is being reciprocatingly driven; and a small-size electrical appliance including the electromotive unit.