1. A virtual computer comprising a plurality of physical CPUs, a plurality of LPARs, and a hypervisor which causes at least one or more logical CPUs constituting the LPAR to share the physical CPUs in a time division manner and thereby allocates the physical CPUs to the logical CPUs, wherein the hypervisor includes: physical CPU management information for associating a physical CPU number which is an identifier of the physical CPU with a CPU group number which is an identifier of a CPU group allocated to the physical. CPU and holding these information; and LPAR management information for associating an LPAR number indicative of an identifier of the LPAR, a number of logical CPUs constituting the LPAR, and a CPU group number, which is an identifier of the CPU group allocated to the LPAR, to each other and holding these information, wherein the hypervisor, when activating the LPAR, prepares, for the each CPU group, an entry of the logical CPU constituting the LPAR to which the CPU group has been allocated, associates, for the each CPU group, an LPAR number of the LPAR which the logical CPU constitutes, a logical CPU number which is an identifier within the LPAR of the logical CPU, and a state of the logical CPU with each other and manages these information as logical CPU management information, and further the hypervisor, in allocating the physical CPU to the logical CPU, causes the physical CPUs belonging to the same CPU group number to be shared in a time division manner and allocates these physical CPUs to logical CPUs belonging to the same CPU group number.