Patent ID: 8043071

Claim:
A vacuum generating unit comprising: a main body, in which a supply port through which a pressure fluid is supplied, a vacuum port connected to a suction mechanism, and an exhaust port for exhausting, to the exterior, the pressure fluid supplied from said supply port are disposed; a vacuum generating mechanism for generating a negative pressure under an action of the pressure fluid supplied from said supply port; a switching valve section having a supply valve and a vacuum breakage valve for switching a pressure of a pressure fluid supplied to said vacuum port between a negative pressure state and a positive pressure state; an atmospheric air introducing valve disposed between said vacuum port and said vacuum generating mechanism, and which is capable of switching the communication state between said vacuum port and the atmosphere, wherein said atmospheric air introducing valve is placed in a valve closed state during a negative pressure state in which negative pressure is generated, and is placed in a valve open state during a positive pressure state in which the negative pressure state is released, thereby causing said vacuum port to communicate with the atmosphere.