PURPOSE: To obtain a lead frame of small pitches by constituting inner leads in a two-layer structure of a surface and rear layers and positioning the inner leads of each layer between each inner lead of the other layer.

CONSTITUTION: Resist films 2 are formed on the surface and rear of a blank metallic plate 1 so that each band of the banded pattern of each film 2 can be positioned between each band of the banded pattern of the other film 2. When the parts without the resist films 2 are etched, the etching progresses and inner leads 3 are separated from each other and, finally, upper inner leads 4 and lower inner leads 5 are formed at small pitches in a two-layer structure. Since outer leads 7 are formed at large pitches in a fan-like form and respectively connected to the inner leads 4 and 5, the leads 7 can be formed by ordinary etching.