To provide a washing apparatus which has such excellent productivity and cost effectiveness that an organic coating film stuck to the object to be cleaned such as a spin coater cup, a semiconductor wafer and a liquid crystal glass substrate can be removed in a short time and the objects to be washed can be washed repeatedly many times without replacing a detergent.

Plurality of washing liquid jetting arms and plurality of rinsing liquid jetting arms, each of which has a plurality of injection nozzles, are respectively disposed rotatably above and below the object to be washed so that each of injection nozzles is directed to the object to be washed. The object to be washed is washed by spraying alkylene carbonate as a washing liquid at a high speed and then the washed object is rinsed by spraying purified water as a rinsing liquid at a high speed. After the washing work using alkylene carbonate and the rinsing work using purified water are completed, the remaining liquid is removed by jetting a gas toward the rinsed object at a high speed. The alkylene carbonate used in the cleaning work is circulated and reused by decomposing a contaminant in the alkylene carbonate by ozone in a washing liquid regeneration tank having a heater.