A counterweight installation device includes: a weight support unit provided on a rear end of a body frame of a construction machine; a weight mounting unit disposed on a counterweight; a pin member for mounting the counterweight adapted to move between a first position at which the weight mounting unit is mounted on the weight support unit and a second position at which the weight mounting unit is dismounted from the weight support unit; and a rod device, one end of which is linked with the pin member and an other end of which extends so as to project to an outside of the counterweight, adapted to move the pin member between the first position and the second position by operation at the other end thereof.