According to one embodiment, a pattern forming method is disclosed. The method includes preparing a processed body including a substrate having a first face, a first layer provided on the first face, a second layer provided on the first layer, and a photosensitive lyophilic/lyophobic original material provided on the second layer. The method includes performing a first process of irradiating light onto one of a first portion at a first position of the material and a second portion at a second position of the material, and making a first contact angle of a liquid with a first region of an upper face of the processed body relatively larger than a second contact angle of the liquid with a second region of the upper face. The method includes performing a first pattern forming process of forming a first pattern by bringing the liquid into contact with the second region.