To provide a linear-type position detection device with high reliability capable of ensuring excellent detection accuracy easily.

Both end parts of a lead screw 11 and a guide shaft 13 arranged in parallel to each other are supported with a holder 8 and a side plate 9. Along with the rectilinear movement of a slider 14 having a tooth portion 15a engaging a spiral groove 11a, along the axial direction of the lead screw 11, a shade 18 having a slit 19 and fixed to the slider 14 moves between a light emitting and a light receiving element 21, 22, and the guide shaft 13 penetrating the slider 14 guides this rectilinear movement. As both end parts of the guide shafts 13 are formed eccentrically with respect to its axial center C, and the relative position relation between the guide shaft 13 and the lead screw 11 changes, when the guide shaft 13 is rotated using both end parts as rotation center axes, mislocation of the shade 18 can be adjusted.