Humidifier for refrigeration showcase

A humidifier for a refrigeration showcase comprising a main body to be fixedly mounted on the top of the showcase, an atomization water tank provided within the main body and having a plurality of ultrasonic vibrators at its bottom, a blower disposed within the main body for drawing in outside air through an intake opening in the main body and supplying the air to the interior of the water tank, ultrasonic oscillation circuits provided for the vibrators respectively in corresponding relation thereto, a plurality of discharge guide tubes mounted on a member located on an upper portion of the water tank and provided in corresponding relation to the vibrators for guiding out of the main body atomized water produced in the water tank by the vibrator driven by the corresponding oscillation circuit, ducts provided for the guide tubes respectively and each having one end communicating with the guide tube and the other end extending into the showcase, control means for varying the oscillation output of the oscillation circuit corresponding to at least one of the vibrators to control the amount of atomized water to be produced, and selection means for selecting whether the amount of humidification is to be made adjustable or constant, said control means being located at a position separately from the main body and the selection means being mounted on the main body.