Spray gun

A spray gun, comprising:

• a casing;
• a cup, including a cup housing and a flexible cup body that is provided in the cup housing;
• a spray nozzle;
• and
• a pump body, provided in the casing, and having a spray chamber in communication with the cup,
• wherein an air discharge structure communicating the cup with an outside area is provided on the pump body, and the cup housing is provided with a hollow portion, such that the flexible cup body is manually squeezable to expel air inside the flexible cup body out via the air discharge structure;
• the air discharge structure comprises an air outlet passage communicating with the cup and an air discharge passage communicating with the outside area, the air discharge passage comprises an air discharge port, and the air discharge structure further comprises a closure cap adapted to open and close the air discharge port;
• and
• a relief valve port communicating with the spray chamber is provided on the pump body, the air outlet passage communicating with the relief valve port, a relief valve assembly being provided at the relief valve port,
• wherein a largest dimension of the air outlet passage and a largest dimension of the air discharge passage extend transversely relative to each other such that the air outlet passage and the air discharge passage define an arrangement of an “Γ” shape.