A linear drive mechanism which moves a detector having sensitivity in a first axial direction, relatively to a workpiece in a second axial direction orthogonal to the first axial direction, the linear drive mechanism includes: a drive shaft extending in the second axial direction; a mover which is supported in a non-contact fashion by the drive shaft and configured to move along the drive shaft integrally with the detector or the workpiece; a guide provided at a position deviated relative to the drive shaft in a third axial direction orthogonal to both the first axial direction and the second axial direction, the guide parallel to the drive shaft; and a resistance force generator which is provided on one of the mover and the guide, and is in contact with the other of the mover and the guide, the resistance force generator generates a resistance force which resists against movement of the mover.