A powder sprayer is described having a barrel or cylinder of synthetic plastic material with an interior baffle cup preferably adhesively secured in the cylinder and closed by a cup closure plate, a check valve being carried therein, the cup bounding a powder chamber and having an air delivery tube, preferably slitted, extending thereinto. The air delivery tube has a threaded end for engagement by a nut rotatable by a manually accessible knob pivotally mounted on an end closure removably sealed to the barrel. The end closure carries a powder delivery tube extending therethrough with its inner end closed and with slits for receiving powder to be delivered through the outer end of the powder delivery tube. The outer end of the powder delivery tube is adapted for attachment of extension tubes and fittings for various types of powder delivery. The powder chamber can be readily refilled by turning the knob and removing the end closure for that purpose. The cylinder at the inlet end has an inlet end collar detachably secured to the cylinder with a hollow tubular piston or plunger also of synthetic plastic material, closed at its inner end and with spaced plates for reception therebetween of a gland or strip packing which serves as an inlet valve.The cap closure plate and inlet end collar bound a pumping chamber within which the tubular plunger is longitudinally movable.The tubular plunger provides a space for storage of extension tubes and nozzle tips and has a resilient closure cap frictionally engaged therewith.