A closed compressor includes a closed vessel having an oil sump in which lubricating oil which is incompatible with a refrigerant is accommodated. A compression mechanism, to which a rotary shaft is connected, is accommodated in the closed vessel. An electric motor is also accommodated in the closed vessel for rotating the rotary shaft to drive the compression mechanism. An oil supply pipe is secured to a lower end of the rotary shaft to draw the lubricating oil contained in the oil sump to the compression mechanism. A generally cylindrical partition wall is formed in the oil sump so as to encircle the oil supply pipe and has a plurality of holes to allow the lubricating oil to pass therethrough. The generally cylindrical partition wall may be replaced with a partition wall that laterally partitions the oil sump into two portions. It is preferred that the plurality of holes includes at least vertically spaced first and second rows of holes with the first row being positioned above the second row. Each hole of the first row has an area greater than the holes of the second row.