A method for evaluating an infection risk in an infection risk evaluation system that evaluates an infection risk by an infectious disease in a children's facility, wherein the method is performed by a computer of the infection risk evaluation system, comprising: obtaining (S11, S12) infection information, which is information regarding a condition of infection of each of one or more family members of a child with the infectious disease and is indicating whether each of the one or more family members is infected with the infectious disease; calculating a first infection risk value, which indicates a degree of an infection risk that the child is infected with the infectious disease; calculating, on a basis of the first infection risk value, a second infection risk value; performing at least either first evaluation, in which the infection risk that the child is infected with the infectious disease is evaluated, and second evaluation; outputting (S109, S111) an evaluation result of at least either the first evaluation or the second evaluation; characterized by obtaining prevalence information, which is information regarding a condition of prevalence of the infectious disease in one or more organizations to which the one or more family members belong and is indicating whether the infectious disease is prevalent in the one or more organizations, wherein the first infection risk value is calculated on a basis of the infection information, the prevalence information, and one or more first infection risk coefficients, which are expressing infection risks between the child and the one or more family members in numbers; the second infection risk value indicates a degree of the child's infection risk of being infected with the infectious disease in a group at the children's facility to which the child belongs, in the first evaluation, the first infection risk value is compared with a certain first reference value, and, in the second evaluation, the second infection risk value is compared with a certain second reference value and the child's infection risk of being infected with the infectious disease in the group is evaluated; identifying (S201, S202) the child whose first infection risk value is larger than the first reference value as a monitoring target child; detecting, using a camera installed in the children's facility, whether the monitoring target child has returned a toy to a toy storage; and spraying, if it is detected that the monitoring target child has returned a toy, a sterilization solution onto the toy from a sterilization apparatus. obtaining (S11, S12) infection information, which is information regarding a condition of infection of each of one or more family members of a child with the infectious disease and is indicating whether each of the one or more family members is infected with the infectious disease; calculating a first infection risk value, which indicates a degree of an infection risk that the child is infected with the infectious disease; calculating, on a basis of the first infection risk value, a second infection risk value; performing at least either first evaluation, in which the infection risk that the child is infected with the infectious disease is evaluated, and second evaluation; outputting (S109, S111) an evaluation result of at least either the first evaluation or the second evaluation; characterized by obtaining prevalence information, which is information regarding a condition of prevalence of the infectious disease in one or more organizations to which the one or more family members belong and is indicating whether the infectious disease is prevalent in the one or more organizations, wherein the first infection risk value is calculated on a basis of the infection information, the prevalence information, and one or more first infection risk coefficients, which are expressing infection risks between the child and the one or more family members in numbers; the second infection risk value indicates a degree of the child's infection risk of being infected with the infectious disease in a group at the children's facility to which the child belongs, in the first evaluation, the first infection risk value is compared with a certain first reference value, and, in the second evaluation, the second infection risk value is compared with a certain second reference value and the child's infection risk of being infected with the infectious disease in the group is evaluated; identifying (S201, S202) the child whose first infection risk value is larger than the first reference value as a monitoring target child; detecting, using a camera installed in the children's facility, whether the monitoring target child has returned a toy to a toy storage; and spraying, if it is detected that the monitoring target child has returned a toy, a sterilization solution onto the toy from a sterilization apparatus.