Provided are a heat-resistant glass fiber which has excellent heat resistance, which is also easy to spin and less expensive and which is suitable as an acoustic material for use in an automobile muffler, and a process for the production thereof. The tread 10 has at least one full depth groove 12. The clock signal and the motor specification database setting signal are transmitted through two of the plural pins which are multi-functional function pins shared by other functions in a normal operation mode. A method for culturing cells is also provided.