To provide a functional element mounting package and a channel structure for mounting a functional element which has a comparatively simple structure and which can easily form a flow channel used as an inlet or an outlet of a fluid to be processed.

The channel structure is such a functional element mounting package constituted of a recessed part 102 defined by a bottom part 101 and a frame member 103 disposed on the bottom part 101; and a support base 113, which is formed on a portion of the bottom part 101 in the recessed part 102, in order to mount the functional element 112 thereon. The bottom part 101 includes a vertical hole 105, making the recessed part 102 communicated with the outside, and the frame member 103 includes a horizontal hole 109 making the recessed part 102 communicated with the outside and a plurality of projecting parts 106, projecting upward from the upper surface of the frame body 103 for mounting a lid member 108 thereon.