Vacuum-generating unit

A vacuum-generating unit comprising:

• a main body section provided with a pressure fluid supply port connected to a pressure fluid supply source, a vacuum port connected to a suction means, and a discharge port for discharging, to the outside, a pressure fluid supplied from said pressure fluid supply port, wherein said main body section is composed of a first block, a second block, a third block and a fourth block which are connected end-to-end and joined in series in a longitudinal direction and each of which is formed to have a flat thin-walled configuration, and said first block, said second block, said third block, and said fourth block are formed to have a substantially identical widthwise dimension respectively;
• an ejector section for generating a negative pressure in accordance with an action of said pressure fluid supplied from said pressure fluid supply port;
• and
• a solenoid-operated valve section and a detecting section carried on said main body section, wherein:
• a passage communicating with said pressure fluid supply port extending through said first and second blocks, a passage communicating with said vacuum port extending through said second and third blocks, and a passage communicating with an air discharge port extending through said first and second blocks for a solenoid-operated valve are arranged substantially in parallel respectively.