The asynchronous circuit insensitive to delays comprises at least one time delay insertion circuit on the propagation path of a signal. The delay insertion circuit comprises, between an input and an output of the signal, a Muller C-element and a plurality of delay circuits connected in series to an output of the Muller C-element. The outputs of the delay circuits are connected to corresponding inputs of a multiplexing circuit having an output constituting the output of the delay insertion circuit. The Muller C-element comprises an input connected to the output of the last delay circuit via an inverter gate, and an input constituting the input of the signal to the delay insertion circuit. The multiplexing circuit control circuit preferably comprises a random generator.