A processing apparatus includes an execution stage which executes each of instruction streams, a first resource counter which counts the number of operating resources used when the execution stage executes a first one of the instruction streams, a second resource counter which holds data of the number of unused ones of the operating resources, and a control circuit which reads the count value of the first resource counter from a management table when a subsequent instruction stream is executed, to control a start of execution of the subsequent instruction stream in accordance with a subtraction result obtained by subtracting the count value from the data. The control circuit checks whether a number of operating resources required by the subsequent instruction stream is secured based on the subtraction result before the subsequent instruction stream starts to be executed.