Variable valve device for engine

A variable valve device, which is capable of automatically canceling a deviation in the relationship between the rotation angle of a control shaft and the lift degree generated because of the disassembling and assembling of an engine, includes a target lift degree calculator that calculates a target lift degree, a motor driver that drives a brushless DC motor that rotates the control shaft until the lift degree reaches the target lift degree, and an automatic deviation canceller that automatically cancels the deviation. More specifically, the magnetic pole pulse pattern of the motor before the engine starts is obtained and it is determined whether the pattern match magnetic pole pulse pattern stored before the engine stops. If they do not match, an idle lift degree is set, the idle lift degree is changed so that the engine speed is within the tolerance range of an idle engine speed, the rotation angle for the idle portion is subtracted from the obtained angle of the control shaft and a reference angle is updated by the difference.