To provide a variable valve device of an internal combustion engine capable of restraining a restriction pin from running over a second stepped section and moving to an intermediate step surface, the restriction pin being in a projecting state in a position corresponding to a bottommost step surface.

A variable valve device of an internal combustion engine comprises a variable valve timing mechanism 10 that changes valve timing and includes restriction mechanisms 30 and 50 that restrict a change to valve timing. The restriction mechanisms 30 and 50 respectively include restriction pins 31 and 51 provided in a vane rotor 15 and stepped sections 45 and 65. The stepped sections 45 and 65 respectively segment opposing surfaces 70 and 80 of a housing rotor 11 into intermediate step surfaces 41 and 61 and bottommost step surfaces 42 and 62. As a result of contact between step surfaces 45A and 65A and the restriction pins 31 and 51, the lag of valve timing VT is restricted. In addition, the intermediate step surfaces 41 and 61 are angled. The amount by which the restriction pins 31 and 51 can project from a vane opposing surface 15B in the end section on the lead side of the intermediate step surfaces 41 and 61 is smaller than that in the end section on the lag side.