The invention discloses an electric braking device for vehicles. According to the invention, a mount member (MTB) is fixed to a supporting member (knuckle) (NKL) by first and second fastening members (TK1, TK2), and a caliper (CPR) is attached to the mount member (MTB) by first and second guide members (GD1, GD2). The motor axis line (Jmt) of an electric motor and the axis line (Jsf) of a shaft member pressing a pressing member (PSN) are different. The electric motor is fixed to the caliper (CPR). When viewed from the axis line direction of the first guide member (GD1), the motor axis line (Jmt) is positioned inside a fastening quadrilateral (Mtk, quadrilateral G-H-L-K) vertical to the axis line (Jgd1) and having as the four corners therefor positions on each axis line (Jgd1, Jgd2, Jtk1, and Jtk2), of GD1, GD2, TK1, and TK2. The motor axis line (Jmt) is also orthogonal to the horizontal plane of the fastening quadrilateral (Mtk). As a result, an electric braking device for vehicles can be provided that has shorter dimensions in the axis direction and suppressed vibration amplitude, and has appropriately arranged therein constituent fittings that are readily affected by vibration.