In this task, you are given a list. This list contains many lists of integers. The list is several items written within a []. Your task is to find the maximum number among the members of each inner list. The output should be a list comprised of the maximums with the same order as the internal lists.
[[-48, -183], [-156, -86, -42, 81, 43, -21], [-124, 89, -90, -108, -5], [68, 16, 89, 60, -139, -58]]