Toner

A toner comprising toner particles each including a toner mother particle and an external additive adhering to a surface of the toner mother particle, wherein

• the external additive includes silica particles,
• the silica particles each include a silica base, a first surface treatment layer covering the silica base, and a second surface treatment layer covering the first surface treatment layer,
• the first surface treatment layer contains a carboxy-modified silicone oil,
• the second surface treatment layer contains a specific copolymer including a first repeating unit represented by general formula (I) shown below and a second repeating unit represented by general formula (II) shown below, and
• the silica particles have a non-ring-opened oxazoline group content of at least 1 μmol/g and no greater than 500 μmol/g as measured by gas chromatography-mass spectrometry,
• where in general formula (I), R1 represents a hydrogen atom or an alkyl group having a carbon number of at least 1 and no greater than 10 and optionally substituted with a phenyl group, and
• in general formula (II), R2 represents a hydrogen atom or an alkyl group having a carbon number of at least 1 and no greater than 10 and optionally substituted with a phenyl group, and an asterisk represents a site that is bonded to an atom in the carboxy-modified silicone oil.