Abstract: A device for manually painting a large surface using a spray gun connected to a paint feed line for the supply of an enamel paint and to a pressure line for the provision of compressed air. After the manual actuation of an operating switch arranged on a handle piece, the spray gun sprays the enamel paint by compressed air via a spray head to apply the enamel paint onto the surface. The spray gun includes means such that it can be moved manually along the surface. The means include an extension rod, at one end of which the spray gun is attached by the handle piece and which is configured such that, when held by an operator on an arm holder configured at the opposite end, it extends from the elbow along the forearm of the operator and beyond the distal end of the forearm.