A reciprocating blade apparatus comprising: a pair of reciprocating blades stacked on one another in a thickness direction, each of the pair of reciprocating blades including: a base as a flat plate extending in a longitudinal direction; and a plurality of teeth protruding in a direction intersecting the longitudinal direction; a transmission case including a reciprocating member having a joint detachably coupled to the base, the reciprocating member being reciprocably supported in the longitudinal direction; and a blade support member attached to the transmission case and configured to sandwich bases of the pair of reciprocating blades therebetween to allow the pair of reciprocating blades to move in the longitudinal direction, wherein: the blade support member holds a space to accommodate the pair of reciprocating blades and is independently attached to the transmission case; characterized in that the pair of reciprocating blades is detachably attached to the blade support member while the blade support member remains attached to the transmission case, wherein: the blade support member includes a pair of support plates (4A, 4B) extending in the longitudinal direction; the pair of support plates (4A, 4B) is fastened at fastening points via spacers configured to hold the space; and the pair of reciprocating blades is supported by the pair of support plates (4A, 4B) at positions different from the fastening points via long holes formed in the bases. a pair of reciprocating blades stacked on one another in a thickness direction, each of the pair of reciprocating blades including: a base as a flat plate extending in a longitudinal direction; and a plurality of teeth protruding in a direction intersecting the longitudinal direction; a base as a flat plate extending in a longitudinal direction; and a plurality of teeth protruding in a direction intersecting the longitudinal direction; a transmission case including a reciprocating member having a joint detachably coupled to the base, the reciprocating member being reciprocably supported in the longitudinal direction; and a blade support member attached to the transmission case and configured to sandwich bases of the pair of reciprocating blades therebetween to allow the pair of reciprocating blades to move in the longitudinal direction, wherein: the blade support member holds a space to accommodate the pair of reciprocating blades and is independently attached to the transmission case; characterized in that the pair of reciprocating blades is detachably attached to the blade support member while the blade support member remains attached to the transmission case, wherein: the blade support member includes a pair of support plates (4A, 4B) extending in the longitudinal direction; the pair of support plates (4A, 4B) is fastened at fastening points via spacers configured to hold the space; and the pair of reciprocating blades is supported by the pair of support plates (4A, 4B) at positions different from the fastening points via long holes formed in the bases. the blade support member holds a space to accommodate the pair of reciprocating blades and is independently attached to the transmission case; characterized in that the pair of reciprocating blades is detachably attached to the blade support member while the blade support member remains attached to the transmission case, wherein: the blade support member includes a pair of support plates (4A, 4B) extending in the longitudinal direction; the pair of support plates (4A, 4B) is fastened at fastening points via spacers configured to hold the space; and the pair of reciprocating blades is supported by the pair of support plates (4A, 4B) at positions different from the fastening points via long holes formed in the bases. the blade support member includes a pair of support plates (4A, 4B) extending in the longitudinal direction; the pair of support plates (4A, 4B) is fastened at fastening points via spacers configured to hold the space; and the pair of reciprocating blades is supported by the pair of support plates (4A, 4B) at positions different from the fastening points via long holes formed in the bases.