The invention describes a field bus system, in particular a field bus system (10), comprising at least one clocked transmitter (16) and one clocked receiver (17) for transmitting data signals to another field bus device (30) or for receiving data signals from the other field bus device (30). To allow interfering emissions to be reduced, a spread spectrum clock (40) is provided which supplies a local spread spectrum clock signal (SST1). The spread spectrum clock signal is sent to the transmitter (16) and the receiver (17) to allow data signals (DO1, DI1) to be transmitted and received synchronously with the local spread spectrum clock signal.