Jam jar works for most everything. Cut out the inside of the lid, put something like a coffee filter, mesh, or a thin piece of cloth, and you're set. You can also put a tongue depressor inside for the mantis to climb on.
L1 ant mantis is very small at 5 mm. You can use something like cocktail cup (12 oz) and place a few twigs in there. Similar to ants, they are good climber, either glass or plastic container will not be any issue.