A magnetic sensor device for detecting linear movement of a moving body includes a magnetic field generation unit and a magnetic field detection unit, which is provided to be capable of detecting the magnetic field generated by the magnetic field generation unit. The magnetic field detection unit is provided to be relatively moveable along a first axis accompanying linear movement of the moving body. The first axis is parallel to the direction of movement of the moving body. The magnetic field generation unit includes a first magnetic field generation unit and a second magnetic field generation unit. The first magnetic field generation unit and the second magnetic field generation unit are arranged substantially parallel to the first axis. A first line segment parallel to a first magnetization direction of the first magnetic field generation unit is inclined with respect to a second axis orthogonal to the first axis. A second line segment parallel to a second magnetization direction of the second magnetic field generation unit is inclined with respect to the second axis. The first line segment and the second line segment are positioned symmetrically with respect to the second axis and intersect each other to open toward the first axis.