PURPOSE: To provide an oil separator which enables narrowing of a layout space and accomplishes a miniaturization and a reduction in cost of a compressor itself.

CONSTITUTION: In an oil separator which is arranged in a discharging system of a compressor, a filter 12 as oil separation material comprising fiber material or the like is housed below a container 91 of the oil separator and the upper part of the container 91 is packed with an oil adsorbing agent such as particulate activated charcoal 22.