An interdental cleaning tool comprising: a base portion made of a synthetic resin; and a soft portion made of an elastomer that covers at least a part of the base portion, the base portion including a handle base portion, and a core base portion that has an elongated shaft-shape and connect continuously to a tip end portion of the handle base portion, the soft portion having at least a cleaning soft portion that covers the core base portion, the handle base portion constituting a handle portion serving as a grip, the core base portion and the cleaning soft portion which constitute a cleaning portion for interdental cleaning, wherein two or more cleaning portion recesses which penetrate the cleaning soft portion and form, in the core base portion, core base portion recesses having a maximum depth of 0.01 mm or more and 0.085 mm or less are formed on each of a first side portion and a second side portion of the cleaning portion at intervals in an axial direction of the cleaning portion, and at least one set of two cleaning portion recesses among plural sets of the cleaning portion recesses paired between the first side portion and the second side portion are formed at an interval in the axial direction of the cleaning portion so as to be avoided from overlapping each other in a circumferential direction of the cleaning portion, wherein the at least one set of the cleaning portion recesses formed at the interval in the axial direction of the cleaning portion has, therebetween, an interval along the axial direction of the cleaning portion, the interval being set to one fourth or more of a maximum axial length of the cleaning portion recesses. a base portion made of a synthetic resin; and a soft portion made of an elastomer that covers at least a part of the base portion, the base portion including a handle base portion, and a core base portion that has an elongated shaft-shape and connect continuously to a tip end portion of the handle base portion, the soft portion having at least a cleaning soft portion that covers the core base portion, the handle base portion constituting a handle portion serving as a grip, the core base portion and the cleaning soft portion which constitute a cleaning portion for interdental cleaning, wherein two or more cleaning portion recesses which penetrate the cleaning soft portion and form, in the core base portion, core base portion recesses having a maximum depth of 0.01 mm or more and 0.085 mm or less are formed on each of a first side portion and a second side portion of the cleaning portion at intervals in an axial direction of the cleaning portion, and at least one set of two cleaning portion recesses among plural sets of the cleaning portion recesses paired between the first side portion and the second side portion are formed at an interval in the axial direction of the cleaning portion so as to be avoided from overlapping each other in a circumferential direction of the cleaning portion, wherein the at least one set of the cleaning portion recesses formed at the interval in the axial direction of the cleaning portion has, therebetween, an interval along the axial direction of the cleaning portion, the interval being set to one fourth or more of a maximum axial length of the cleaning portion recesses.