A machine tool 1 comprises a bed 11, a column 12, a spindle head 15, a spindle 16, a saddle 17, a table 18, a feed mechanism for moving the spindle head 15, the saddle 17 and the table 18 in Z-axis, Y-axis and X-axis directions respectively, a position detector for detecting the positions of the spindle head 15, saddle 17 and table 18, a controller for feedback controlling the feed mechanism, a position detector 51 for detecting the position of the spindle head 15, a position detector 54 for detecting the position of the spindle head 15, a position detector 57 for detecting the position of the table 18, and a measurement frame 50 which is configured with a different member from the bed 11 and the column 12 and on which readers 53, 56, 59 of the position detectors 51, 54, 57 are disposed.