Unexpexted 404 in express.js

I really don't understand why node(express) just render index page and return 404 for other pages ("comproAffitto" in the example).

app.js

var index = require('./routes/index');
var comproAffitto= require ('./routes/comproAffitto');

...
...

app.use('/', index);
app.use('/comproAffitto', comproAffitto);

routes/index.js

var express = require('express');
var router = express.Router();

/* GET home page. */
router.get('/', function(req, res, next) {
res.render('index', { title: 'Express' });
});

module.exports = router;

routes/comproAffitto.js

var express = require('express');
var router = express.Router();

/* GET comproAffitto page. */
router.get('/comproAffitto', function(req, res, next) {
console.log("dentro");
res.render('comproAffitto', { title: 'Exprrress' });
});

module.exports = router;

html href

<a href="/comproAffitto/" class ....

console log

GET /comproAffitto/ 404

where is the problem?

thank you all

via tommasoballardini