A method for etching a silicon oxide film on a target substrate where an etching area is partitioned by pattern layers and stopping the etching before a base layer of the silicon oxide layer is etched is disclosed. The method includes heating the target substrate in a vacuum atmosphere and intermittently supplying, as an etching gas, at least one of a processing gas containing a hydrogen fluoride gas and an ammonia gas in a pre-mixed state and a processing gas containing a compound of nitrogen, hydrogen and fluorine to the target substrate from a gas supply unit multiple times.