A surface texture measuring instrument provided with a near-field measuring unit (30) including a near-field probe (33) that forms a near-field light at a tip end thereof when a laser beam is irradiated, a laser source (35) that generates the laser beam to be irradiated on the near-field probe (33), a detection element (38) that detects scattering effect of the near-field light generated when the near-field probe (33) is moved close to a workpiece (1), and an actuator (32) that displaces the near-field probe (33) and the workpiece (1) in a direction moving close to/away from each other, includes: a laser length-measuring unit (20) that measures a relative distance between a reference position and the workpiece (1) in the vicinity of the tip end of the near-field probe (33) or a relative distance between the reference position and the near-field probe (33).