To implement a handrail mounting device which does not need work of drilling, structural bar cutting, etc., dispenses with a temporary insert, an anchor bolt, etc. when a temporary handrail is mounted, eliminates the necessity of plastering in the construction field, and contributes to shortening of a handrail mounting period.

The handrail mounting device is formed of: a precast concrete block 10 constituting a fence setting portion; an anchor bar 11 erected from the precast concrete block 10 at a location that does not cross structural bars 14 of the precast concrete block 10 in a manner partly protruding from the same; a permanently set handrail support 13; and a reinforcing pipe 12 inserted into the permanently set handrail support 13, for reinforcing the same.