To provide a tower-climbing scaffold device that does not require carrying or transportation thereof because the device is permanently-installed to legs of a power transmission steel tower while the device can be protruded from the legs to be used as a scaffold when a regular operator climbs the tower.

A tower-climbing scaffold device includes: an adaptor 2 fixed into an attaching hole 51 of an object to be climbed by insertion and has a female screw part 4 on the inner periphery of an insertion hole 3; a rodlike member 20 supported in the insertion hole freely movable forward/backward and includes a falling prevention member 22 that prevents falling from the insertion hole and a male screw part 24 that is screwed into a female screw part; and a scaffold bolt 30 having a head 26 provided for the other end side of the rodlike member, in which when the rodlike member is sunk into the insertion hole, the male screw part is screwed into the female screw part to prevent the rodlike member from being protruded outside the insertion hole while the rodlike member can be protruded outside the insertion hole by canceling the screwing.