Abstract: A safety door has safety bolts provided at two opposite peripheral edges of the door leaf. By a locking mechanism apparatus, the safety bolts can be shifted into assigned guideways in such a manner, that they protrude beyond the corresponding peripheral edge of the door leaf in a locked position and are accommodated in the door leaf in an unlocked position. The locking mechanism apparatus has a slide rod which can be shifted in its longitudinal direction essentially transversely to the guideways and with which the safety bolts are mechanically coupled. Precisely one safety bolt is carried in each guideway. The safety bolts assigned to the one peripheral edge and those assigned to the opposite peripheral edge are disposed offset to one another.