The invention provides a variable valve device that can prevent a connection pin from popping out to cause noise and enable smooth connection of a rocker arm. A cylinder cover (10) is provided with a first air inlet rocker arm (25) and a second air inlet rocker arm (27) that are adjacent to each other, wherein the first air inlet rocker arm swings through an air inlet cam (22c) disposed on a cam shaft (22) to close an air inlet valve, and the second air inlet rocker arm is connected or disconnected with the first air inlet rocker arm (25) via a connection pin (54). The outer wall of the cylinder cover is equipped with an electromagnetic execution mechanism (21) that enables the connection pin (54) to move forward and backward between the first air inlet rocker arm (25) and the second air inlet rocker arm (27). The variable valve device has a crank angle sensor (65) for detecting a rotation positiono of a crank shaft and a control device (66) for controlling working of the electromagnetic execution mechanism (21) on the basis of a crank angle detected by the crank angle sensor (65).