A method of and an apparatus for producing containers from thermoplastic sheet material are disclosed. The sheet material is heated to its plastic state and clamped at its periphery. Then a moulding die is advanced substantially normally towards and against the clamped heated sheet material. The moulding die has a temperature below the temperature of the heated clamped sheet material and is provided with a projecting peripheral portion and/or a recessed central portion directed towards the sheet material. By further advancing the moulding die by a predetermined amount against the sheet material, this is deformed and shaped into the desired container. A cooling air flow is directed against the clamped heated sheet material in a region thereof adjacent to the peripheral portion of the moulding die to avoid reduced wall thickness at the edge and corner regions of the container by excessive stretching of the sheet material. Thus, stable containers of uniform wall thickness may be produced.