A glassy adhesive including a composition containing at least: a polysilazane compound having structures represented by the following formulae (A-1) and (A-2) and not containing a hydrosilyl group; and a curing catalyst, where a mole ratio of the component (A-1) to the component (A-2), which is (A-1):(A-2), is within a range of 3:7 to 7:3, the composition has a non-volatile content of 50 mass % or more, when the composition being heated at 105° C. for 3 hours, and the curing catalyst is at least one selected from the group consisting of an organic acid, a simple substance of a d block element belonging to the fourth period of the periodic table, a platinum group element, and an amphoteric element, and a compound containing the element. This provides an adhesive that is low-cost, has high UV resistance, and in which cracks and so forth do not occur even after a reflow process.