An electrical connection box that is applied to a wire harness includes: a housing that includes a housing space portion that is formed therein and houses therein a first electronic component, and a housing recessed portion that is partitioned below the housing space portion in a vertical direction by a partition wall portion, closed on one side in a horizontal direction, provided with an opening on the other side in the horizontal direction, and houses therein a second electronic component; and a latch mechanism that is positioned within the housing recessed portion and latches the second electronic component and the housing in a state that the second electronic component is housed in the housing recessed portion.