AbstractThe constant of the two‐photon interband absorption of light (TPA) in a semiconductor placed in external, parallel quantizing electric and magnetic fields is calculated. It is shown that the TPA constant near each Landau level must have an oscillatory behaviour due to the presence of discrete Stark levels, that is, at high electric field strengths the “Stark ladder” must be observed. The following particular cases are considered: the one‐photon absorption (OPA), the two‐photon electroabsorption (TPEA), and the two‐photon magneto absorption (TPMA).