A needle plate includes a first needle plate secured on a bed and a second needle plate detachably attached to the first needle plate. An engagement mechanism includes an engagement member formed at the first needle plate and an engagement subject member formed at the second needle plate, and retains the second needle plate with the first needle plate through engagement of the engagement member and the engagement subject member. A switching element switches positioning of the second needle plate relative to the first needle plate, wherein when in a first position, the second needle plate is secured in contact with the first needle plate with the engagement mechanism engaged, and when in a second position, the second needle plate is distanced from the first needle plate.