Extremely bright short-pulsed radiation delivered by the free electron laser (FEL) facilities is used in various fields of science and industry. Most of the experiments carried out using FEL radiation are dependent on the temporal durations of these photon pulses. Monitoring the FEL pulse lengths during these experiments is of particular importance to better understand the measurement results. One of the methods to measure the temporal durations of the FEL pulses is the THz streak camera. This contribution presents simulation of the THz streak camera concept that allows better understanding of the measurement technique and estimating measurement accuracies achievable with this method.