BNCT of skin malignant melanoma bas been developed in Japan since 1972. Primary lesions and unobservable satellite metastasis can be selectively treated with this technique. The clinical results related to 18 patients treated in Japan up to January 1996 are analysed in ref. 1. The survival rate after two or more years resulted to be 78%, regardless the level of melanoma progression. 10B-paraboronphenylanine (BPA) was used as the boron carrier to the tumour. The patiens were irradiated at a research reactor facility for 1-2 hours with thermal neutrons and the related maximum fluences at the tumour sites were in the range (1.0-2.0)x1013 cm-2.The design of the accelerator-based neutron source for BNCT of skin melanoma discussed in the present work is described in ref. 3. Neutrons are produced by bombarding a thick beryllium target with 7 MeV deuterons. The target is contained in a heavy water moderator in turn enclosed in a graphite structure. Lead filters are placed on the Faraday cup containing the beryllium target and on the heavy water container to reduce the prompt gamma ray dose. The experimental verification of the accelerator-based source was performed at the CN Van De Graaff accelerator of the Laboratori Nazionali di Legnaro (LNL, Italy). Measurements of thermal fluence uniformity and prompt gamma ray dose at the irradiation position, together with estimates of the neutron fluences inside an Alderson phantom are discussed in this paper.