The electric motor-driven submersible mixer is designed for operation in the explosive environment of the biogas plant. Agitator can be adjusted to the mast by means of motor support for height adjustment purposes. Due to roller guidance, the mixer can be smoothly lowered and lifted without friction, even if the pull of the hauling cable is slightly angular. The geared motor is made of cast iron with spheroidal graphite and painted on the surface. The propeller is galvanized and the motor support is made of stainless steel. Submersible mixer is a water pressure-tight mono-block unit for driving the three-vane propeller.