To provide a wire for an interdental brush, which has superior workability in manufacturing, and durability and operationality such as spring back, buckling and breakage, and to provide an interdental brushware with the use of the wire.

The wire for the interdental brush is made of a wire of an austenitic stainless steel which consists of mass, 0.07% or less C, 0.6% or less Si, 13-17% Mn, 2.0-5.0% Ni, 16.0-20.0% Cr, 0.4-2.0% Mo, 0.3-0.60% N and 0.3-1.0% Cu, and has a Ni equivalent defined by the following expression adjusted to 30-40%: Ni equivalent (%) = Ni% + 0.65 Cr% + 0.98 Mo% + 1.05 Mn% + 0.35 Si% + 12.6 (C+N)%; and has fracture elongations of 35-60% in a tensile test for the wire. The interdental brushware is manufactured by using the wire.