The Museum is a place acquired in all of the Denpa Men games. In the Denpa Men 1 and 2, it is acquired with parts whereas in the Denpa Men 3 it is already on Digitoll when you begin the game.
The Denpa MenEdit
In the first Denpa Men game, the Museum is a place which shows the antennas which you have acquired. It is useful for showing you what you have and haven't obtained in your travels. Unlike in the other Denpa Men games, if you catch a Denpa Man with a skill you have not seen before and it is already above tier 1, it will only appear as that tier in the Museum. To get the lower tiers, you must equip the Antenna Down -1 and the Antenna Down -2.
The Denpa Men 2Edit
In the Denpa Men 2, the Museum shows records for the monsters you have seen and the items you have acquired, as well as the antennas you have encountered. You can use this information yet again to see what you have and have not defeated (monster wise) or acquired. It is also useful for seeing what each monster drops and the rarity order for each drop from each monster.
The Denpa Men 3Edit
In the Denpa Men 3, the Museum shows records for pretty much everything in-game you can acquire. This includes fish, plants, interior decorations for homes, items, monsters and antennas. It is a very handy structure in the game as you can look for what you need and yet again, what monster drops you need and which fish you may need to complete getting every fish etc. It is basically a hotspot for information on everything you can acquire in The Denpa Men 3 game. It serves a very great purpose for those in The Denpa Men 3 who call themselves collectors or completionists as they can see how many of each thing they are missing and where they slot under each category.