Welded structure and machinery

Provided is a welded structure configured so as to be able to appropriately handle the relationship between one intermittent weld for securing a long member on a base metal and another intermittent weld for securing a plate-shaped member on the long member according to the predominant type of load acting on the long member. On a body frame (21), which is the base metal, the lower long side of a beam member (41), which is the long member, is secured by one intermittent weld (42a, 42b, 42c). On the upper long side of the beam member (41), a top plate (43), which is the plate-shaped member, is secured by another intermittent weld (44a, 44b, 44c). In regions where loads predominantly act to twist the top plate (43) with respect to the beam member (41), parallel weld sections (Wpar), in which the intermittent welds (42a, 42c) and the intermittent welds (44a, 44c) are welded in a side-by-side weld form, are used. In regions where loads predominantly act to bend the top plate (43) with respect to the beam member (41), zigzag weld sections (Wzig), in which the intermittent welds (42b) and the intermittent welds (44b) are welded in a staggered weld form, are used.