A magnetic lock device (20) comprising: a lock shaft (21) having a contact section (210) capable of coming in contact with a roller of a piston rod in a hydraulic actuator; a transmission shaft (24) configured separately from the lock shaft (21) and coming in contact with an end surface (214) of the lock shaft (21); and a magnetic section (30) that locks (restricts movement to the right side, in the diagram, of) the lock shaft (21), the transmission shaft (24), and a plunger (31), by drawing the plunger (31) to a suction unit (331) side by using magnetic force. The lock shaft (21) is surface-hardened and is formed so as to have increased hardness. The transmission shaft (24) is formed using a non-magnetic body.