A method for manufacturing a fine hollow protruding tool (1) having an opening portion (3h) of the present invention includes: a protrusion forming step of contacting a protrusion-forming projecting mold part (11A) including a heating means with first face (2D) of a base material sheet (2A), and inserting the protrusion-forming projecting mold part (11A) while softening, by heat, a contact point (TP) to form a fine hollow protrusion (3) which projects from the second face (2U) and which does not penetrate the projecting base material sheet (2A)； a cooling step of cooling of cooling the fine hollow protrusion (3) in a state where the protrusion-forming projecting mold part (11A) is inserted therein； a release step of, after the cooling step, withdrawing the protrusion-forming projecting mold part (11A) to form a fine hollow protrusion (3) having a hollow interior； and an opening portion forming step of forming an opening portion (3h) which penetrates an interior portion of the fine hollow protrusion (3), at a position offset from a tip portion of the formed fine hollow protrusion (3).
