To evacuate a press member for preventing the float up of a printed board without using an exclusive drive source so as not to disturb a tool replacing operation, at the tool replacing time.

When a spindle unit 1 is lifted to a tool changing position, a cam follower 27 parted from an operation pin 38 is engaged with the operation pin 38 and moved in the mutually approaching direction and thereby, a pair of open/close arms 24 provided on the lower side of a pressure foot 20 are opened from the press position A closed by a spring 28 force to an evacuation position B and the tip of the open/close arm 24 is positioned to the outside of a tool passing area S for passing a tool pot at the tool changing time.