This article describes the development of turbomolecular pumps at Alcatel over more than 20 years. It shows the changes from the initial molecular pumps and turbomolecular pumps to the present technology of hybrid turbomolecular pumps. The different bearing technologies used in pumps such as ball bearing, gas bearing and maglev bearing technologies are described. The changes in the rotor design of MDP and TMP are explained by the improvement of calculation methods such as analytical calculation for molecular and viscous flow, Monte Carlo simulation for the molecular flow, direct Monte Carlo simulation for transition flow and simulation with CFD codes for viscous flows in 2D and 3D.