To provide a mask which can endure use for a long time, and can be used for forming an isolated pattern with a high aspect ratio.

The fabricating method of the mask includes the step S11 forming a soft material layer by disposing a soft material having positive photosensitivity and stickiness or adhesiveness on a material as a target of machining, the steps S12 to S14 forming a hard material layer by disposing opaque hard material in which a desired mask pattern has been formed in advance on the soft material layer, and the steps S15, S16 forming the mask pattern in the soft material layer by exposing the soft material layer to light and developing it by using the hard material layer as a photo mask.