To provide a method for heating a solution containing cumene hydroperoxide by which a required heat transfer area of equipment for heating the solution can be reduced and thermal decomposition of the cumene hydroperoxide can be suppressed to suppress the formation of unfavorable by-products.

This method for heating the solution containing the cumene hydroperoxide comprises keeping a container part in which the solution is held during heating in a state of full solution. Specifically, the method can be used in a heating step comprising the following steps. An oxidizing step which is the heating step of oxidizing cumene and thereby providing the cumene hydroperoxide and heating the solution which is a reactional solution obtained in the oxidizing step and containing the cumene hydroperoxide, a concentrating step of concentrating the reactional solution after the heating step, and an epoxidizing step of reacting the cumene hydroperoxide in the reactional solution after the concentrating step with propylene and thereby affording propylene oxide and cumyl alcohol.