A pattern forming method, includes: (i) a step of applying a resist composition whose solubility in a positive tone developer increases and solubility in a negative tone developer decreases upon irradiation with an actinic ray or radiation, the resist composition containing a resin capable of increasing a polarity by the action of an acid; (ii) an exposure step; (iii) a step of performing development by using a negative tone developer to form a resist pattern; and (iv) a step of causing a crosslinked layer-forming material to act on the resist pattern to crosslink the resin constituting the resist pattern and the crosslinked layer-forming material, thereby forming a crosslinked layer. According to the present invention, a method for forming a pattern having an effectively micro-dimensioned trench or hole pattern without generation of a scum is provided.