Provided is an interdental cleaning tool which has a simple configuration and can effectively prevent an occurrence of breakage of a core base portion when inserting the interdental cleaning tool into an interdental space or during interdental cleaning without reducing the productivity of the interdental cleaning tool, and provided is a method for manufacturing the interdental cleaning tool. A plurality of cleaning portion recesses (14) which penetrate a cleaning soft portion (21) and form recesses (14a) in a core base portion (12) are formed on each of a first side portion and a second side portion of a cleaning portion (2) at an interval in an axial direction of a cleaning soft portion (21), and at least one of the plurality of cleaning portion recesses (14) is formed so that an opening of the core base portion recess formed in the core base portion has a shape elongated in the axial direction of the cleaning portion.