To provide manufacturing processes for precast concrete beam and column members capable of placing concrete separately and neatly in a section of a boundary between a beam part and a column part in accordance with design.

Reinforcing bars for the beam part and the column part are assembled into a form for beam 22 and a form for column 24. Partitioning plates 26 are arranged at open ends 36A, 38A of a first form for beam 32 and a second form for beam 34, respectively, to partition concrete placed spaces 36, 38 for forming the beam part and a concrete placed space 42 for forming the column part while a main reinforcing bar T1 is inserted among them. Concrete C1 for beam is placed in the concrete placed spaces 36, 38 for forming the beam part and is cured. Next, the partitioning plates 26 are removed and the form for column 24 is assembled on the open ends 36A, 38A of the first form for beam 32 and the second form for beam 34. Then, concrete C2 for column is placed in the concrete placed space 42 in the form for column 24 and is cured.