A positive-charging toner having a work function of 5.0 eV to 5.4 eV, the work function being determined according to the description, and the positive-charging toner comprising a toner particle containing a binder resin, wherein the binder resin contains a polymer A that is a resin exhibiting crystallinity, the polymer A contains a first monomer unit derived from a first polymerizable monomer, and a second monomer unit derived from a second polymerizable monomer that is different from the first polymerizable monomer, wherein the first monomer unit and the second monomer unit have SP values of SP 11 (J/cm 3) 0.5 and SP 21 (J/cm 3) 0.5 respectively, the SP values are calculated by Fedors method as indicated in the description, the SP 11 and the SP 21 satisfy a relationship represented by formula, 3.00 ≤ SP 21 − SP 11 ≤ 25.00 and the first polymerizable monomer is at least one selected from the group consisting of (meth)acrylic acid esters having a C18 to C36 alkyl group, and wherein the first monomer unit is contained in the polymer A in a content of from 5.0 to 60.0 mol% with respect to a total number of moles of all monomer units in the polymer A, and the second monomer unit is contained in the polymer A in a content of from 20.0 to 95.0 mol% with respect to the total number of moles of all monomer units in the polymer A, wherein the second polymerizable monomer is at least one selected from the group consisting of Formulae and below: where, X represents a single bond or a C1 to C6 alkylene group; R 1 represents a nitrile group (-C≡N), an amide group i.e. -C(=O)NHR 10 where R 10 is a hydrogen atom or a C1 to C4 alkyl group -, a hydroxy group, -COOR 11 - where R 11 is a C1 to C6 alkyl group or a C1 to C6 hydroxyalkyl group, a urethane group i.e. -NHCOOR 12, where R 12 is a C1 to C4 alkyl group, a urea group i.e. -NH-C(=O)-N(R 13)2 where R 13 are each independently a hydrogen atom or a C1 to C6 alkyl group, -COO(CH 2) 2 NHCOOR 14 where R 14 is a C1 to C4 alkyl group; or -COO(CH 2) 2 -NH-C(=O)-N(R 15) 2 where R 15 are each independently a hydrogen atom or a C1 to C6 alkyl group; R 2 represents a C1 to C4 alkyl group; and R 3 represent a hydrogen atom or a methyl group. the work function being determined according to the description, and the positive-charging toner comprising a toner particle containing a binder resin, wherein the binder resin contains a polymer A that is a resin exhibiting crystallinity, the polymer A contains a first monomer unit derived from a first polymerizable monomer, and a second monomer unit derived from a second polymerizable monomer that is different from the first polymerizable monomer, wherein the first monomer unit and the second monomer unit have SP values of SP 11 (J/cm 3) 0.5 and SP 21 (J/cm 3) 0.5 respectively, the SP values are calculated by Fedors method as indicated in the description, the SP 11 and the SP 21 satisfy a relationship represented by formula, 3.00 ≤ SP 21 − SP 11 ≤ 25.00 and the first polymerizable monomer is at least one selected from the group consisting of (meth)acrylic acid esters having a C18 to C36 alkyl group, and wherein the first monomer unit is contained in the polymer A in a content of from 5.0 to 60.0 mol% with respect to a total number of moles of all monomer units in the polymer A, and the second monomer unit is contained in the polymer A in a content of from 20.0 to 95.0 mol% with respect to the total number of moles of all monomer units in the polymer A, wherein the second polymerizable monomer is at least one selected from the group consisting of Formulae and below: where, X represents a single bond or a C1 to C6 alkylene group; R 1 represents a nitrile group (-C≡N), an amide group i.e. -C(=O)NHR 10 where R 10 is a hydrogen atom or a C1 to C4 alkyl group -, a hydroxy group, -COOR 11 - where R 11 is a C1 to C6 alkyl group or a C1 to C6 hydroxyalkyl group, a urethane group i.e. -NHCOOR 12, where R 12 is a C1 to C4 alkyl group, a urea group i.e. -NH-C(=O)-N(R 13)2 where R 13 are each independently a hydrogen atom or a C1 to C6 alkyl group, -COO(CH 2) 2 NHCOOR 14 where R 14 is a C1 to C4 alkyl group; or -COO(CH 2) 2 -NH-C(=O)-N(R 15) 2 where R 15 are each independently a hydrogen atom or a C1 to C6 alkyl group; R 2 represents a C1 to C4 alkyl group; and R 3 represent a hydrogen atom or a methyl group.