The linear motion drive system is capable of optionally changing a
position of a linear rail with respect to a pedestal. The linear motion
drive system comprises: a pedestal section; a linear rail arranged in
parallel with respect to the pedestal section; a rail holder attached to
the pedestal section, the rail holder holding the linear rail on the
pedestal section; and a moving body linearly reciprocally moving along
the linear rail. The rail holder is slidably attached to and fixed to the
pedestal section by an attaching mechanism so as to optionally change a
position of the rail holder with respect to the pedestal section.