The present invention relates to a top cap assembly and a button-type secondary battery including same, and relates to: a top cap assembly in which a stepped portion formed between a base plate and an electrode terminal is eliminated, and a welding point is raised, thus making it possible to enhance the welding quality and increase the assembly yield of batteries, and damage to an electrode assembly due to welding heat is minimized, thus making it possible to ensure the quality and stability of the batteries; and a button-type secondary battery including same. The button-type secondary battery according to the present invention has a greater diameter than height, and comprises: a can body which is open at the upper end and has an accommodation space formed therein; an electrode assembly accommodated in the accommodation space of the can body; and a top cap assembly which is coupled to the can body and covers the upper end of the can body. The top cap assembly includes: a base plate which is formed in a flat plate shape and bent upward in a circumferential region; an electrode terminal which is formed in a flat plate shape and rests on the upper portion of the base plate, and has a protrusion portion protruding downward in a central region; and an insulating member provided between the base plate and the electrode terminal.