Fine resin particle and application thereof

A fine resin particle comprising a copolymer of at least one monofunctional vinylic monomer (A) unit with a cyclic structure in a molecular structure, at least one monofunctional alkyl (meth)acrylate-based monomer (B) unit, at least one multifunctional (meth)acrylate-based monomer (C) unit, and at least one multifunctional thiol (D) unit, wherein a polymer consisting only of a monofunctional alkyl (meth)acrylate-based monomer (B) has a glass transition temperature of 50° C. or lower,

• wherein relative to a total of 100 parts by mass of all copolymer units, an amount of the at least one monofunctional vinyl monomer (A) unit with a cyclic structure in a molecular structure is 5 to 80 parts by mass, an amount of the at least one monofunctional alkyl (meth)acrylate monomer (B) unit is 5 to 80 parts by mass, an amount of the at least one multifunctional (meth)acrylate monomer (C) unit is 5 to 50 parts by mass, and an amount of the at least one multifunctional thiol (D) unit is 0.05 to 20 parts by mass, and
• wherein a 5% thermal decomposition initiation temperature under a nitrogen atmosphere is 345° C. or higher and/or a weight loss rate after holding at 270° C. for 40 minutes under an air atmosphere is 30% or less.